The present invention relates to an improved system for the playback of conventional disc phonograph records, and more particularly to a system using a laser beam to replace the conventional stylus or pick-up needle.
Present phonograph record playback devices make use of a stylus pick-up and electro-mechanical transducer to convert the groove modulations into electrical signals. Inherent to this technique are the problems of wear, limited bandwidth, distortion, and noise transients from scratches, contamination, and record warp.
The record is subject to wear, for example, from the stylus pick-up which is physically in contact with the groove walls. This results in loss of fidelity and distortion as the record is replayed over and over. Similarly, the stylus itself is subject to wear, which also reduces the fidelity of the reproduced sound.